Process of and apparatus for manufacturing prussic acid.



0. LIEBKNECHT.

PROCESS OF AND APPARATUS FOR MANUFACTURING PRUSSIC ACID.

APPLICATQION FILED JAN.2l,19l7.

1,235,342. Patented July 31, 1917.

Ally/ Inventor:

UNITED STATES PATENT OFFICE.

OTTO LIEBKNECHT, ,OF FRANKFORT-ON-THE-MAIN, GERMANY, ASSIGNOR TO THE ROESSLER & HASSLACHER CHEMICAL COMPANY, OF NEW YORK, N. Y., A COB.-

PORATION OF NEW YORK.

PROCESS OF AND APPARATUS FOR MANUFACTURING PRUSSIC ACID.

Specification of Letters Patent.

Patented Jlil 31, 191 7.

Application filed January 27, 1917. Serial No. 145.019.

- subject of the German Emperor, and resident of Frankfort-on-the-Main, Germany, have invented certain new and useful Improvements in Processes of and Apparatus for Manufacturing Prussic Acid, of which the following is a specification.

' My invention relates to the manufacture of prussic acid by means of the electric are, its object being to provide improvements in a method of, and a device for, manufacturing prussic acid, whereby the undesirable separation of elementary carbon is practically, or entirely, prevented.

In manufacturing prussic acid by conducting gases containing carbon, nitrogen, and hydrogen, through an electric are, these gases, under the action of the high temperature required for the proper treatinent, are part1 subject'to a decomposition resulting in t e formation of elementary carbon. This carbon'depositing in the form of soot upon the insulators of the current conductors, breaks the insulations and thereby, is liable to cause short-circuits which under certain conditions might even endanger the furnace.

This drawback cannot be entirely removed by diluting the gases to a high degree, viz. treating the gases in a condition in which they contain but a comparatively small proportion of carbon. Not only that this step is not able to entirely overcome the said drawback, moreover the same causes an increased consumption of electrical energy and, as must be expected, yields the prussic acid in a very diluted condition.

It is the object of my present invention .to provide improvements by which these drawbacks are overcome, or at least diminished to a relatively harmless degree. I attain this protection by enveloping the insulations and current conductors within the furnace, especially at the places where both come in contact with one another, by means of gases containing no elementary carbon. For this purpose I prefer to employ such gases which contain but small proportions of combined carbon, or none of such carbon, at all to remove any possibility of such gasesbecoming decomposed and separating carbon. under the action of the heatradiated by the electric arc.

In order to securely protect the electrodes as well as their insulation from deposits cf thev elementary carbon becoming free during the synthesis, I prefer to place them in a slde chamber or side compartment adjoining the furnace chamber proper and opening into the same.

,The gases I employ for protecting the insulations, at the same time produce a cooling effect upon the same. The thus employed gases may be fed into the side chamber in a direction substantially tangential to the objects to be enveloped.

In the accompanying drawing Figure 1 is a vertical section through a portion of the reaction chamber; Fig. 2 is a sectional view of the apparatus shown in Fig. 1 along the line 22; and Fig. 3 is a side elevation of the complete apparatus, parts being shown in section.

Similar letters of reference indicate similar parts throughout the several views.

a indicates the furnace chamber proper and a the furnace wall; 6 indicates a side chamber connecting with chamber a and containing an electrode 0 with its insulation tube d, 6 indicates a gas tight packing; pipes g, g, 71. and k are provided to introduce the gases into chamber 6; pipe f serves as an inlet into insulating tube 03. The pipes are preferably disposed so as to introduce the gases conducted by them tangentially to the walls of chamber 72 or tube 11, respectively, as shown in Fig. 2.

In Fig. 3, I have shown the complete apparatus assembled. Connecting with furnace chamber a; at one end is a pipe 5 for supplying the reaction gases. Pipe j at the opposite end from pipe 71 serves as anexit for the products of the reaction. is indicates a spring controlled check valve which may .be set to maintain any desired pressure in furnace chamber a.

I pass through the pipes f, g and h and g and 71. gases either entirely free from carbon or which contain the latter only in such form that it will not be reduced from its compound under the conditions of the operation.

Such gases are for instance nitrogen, carhon monoxid or a mixture of these, either with or without hydrogen, in the form of producer gas; these gases introduced into the side-chamber I) serve to avoid what otherwise would'take place, viz: the deposition of the reaction carbon on the electrodes owing to decomposition of the applied hydrocarbon by heat which would finally cause sliort-circuits; it is obvious that these ases finally mix with ases which I introduce into the reaction 0 amber proper.

I claim I 1. The process of producing hydrocyanic acid comprising heating a gaseous mixture containing carbon, nitrogen and hydrogen by a high voltage are while surrounding the conducting parts and the insulation thereof with gases unable to segregate carbon.

2. The process of producing hydrocyanic acid, comprising heating a gaseous mixture containing carbon, nitrogen and hydrogen by a high voltage are while surrounding the conducting parts and the insulation thereof at the places of contact Within the furnace with ases unable to segregate carbon.

3. The process of producing hydrocyanic acid comprisin heating a gaseous mixture containing car on, nitrogen and h drogen by a high voltage are while surroun ing the V conducting fparts and the insulation thereof wlth gases ree from carbon.

4. The process of producing hydrocyanic acid comprising heating a gaseousmixture containing carbon,'nitrogen and hydrogen by a high voltage are whlle surrounding the conducting parts and the insulation thereof with gases containing insufiicient carbon to enable material quantities of carbon to segre gate.

5. In amapparatus for the production of hydrocyanic acid by heating a gaseous mixture containing carbon, nitrogen, and hydrogen by a high voltage are, a furnace space proper, an inlet and an exit pipe for reaction of gases, spaces connecting with and adjoining the furnace space proper, a

conductor in each of said ad oining spaces, insulation for said conductors and means for admitting gases into said adjoining spaces to protect the conductors and their insulation.

In testimony whereof I have signed my name to this specification in the presence of two subscribing Witnesses.

OTTO LIEBKNECHT.

Witnesses:

JEAN GRUND, HARRY E. OARLsoN. 

